title: Plasma metanephrine for assessing the selectivity of adrenal venous sampling.
abstract: Adrenal vein sampling is used to establish the origins of excess production of adrenal hormones in primary aldosteronism. Correct catheter positioning is confirmed using adrenal vein measurements of cortisol, but this parameter is not always reliable. Plasma metanephrine represents an alternative parameter. The objective of our study was to determine the use of plasma metanephrine concentrations to establish correct catheter positioning during adrenal vein sampling with and without cosyntropin stimulation. We included 52 cosyntropin-stimulated and 34 nonstimulated sequential procedures. Plasma cortisol and metanephrine concentrations were measured in adrenal and peripheral venous samples. Success rates of sampling, using an adrenal to peripheral cortisol selectivity index of 3.0, were compared with success rates of metanephrine using a selectivity index determined by receiver operating characteristic curve analysis. Among procedures assessed as selective using cortisol, the adrenal to peripheral vein ratio of metanephrine was 6-fold higher than that of cortisol (94.0 versus 15.5; P<0.0001). There were significant positive relationships between adrenal to peripheral vein ratios of cortisol and metanephrine for cosyntropin-stimulated samplings but not for nonstimulated samplings. Receiver operating characteristic curve analysis indicated a plasma metanephrine selectivity index cutoff of 12. Using this cutoff, concordance in sampling success rates determined by cortisol and metanephrine was substantially higher in cosyntropin-stimulated than in nonstimulated samplings (98% versus 59%). For the latter procedures, sampling success rates determined by metanephrine were higher (P<0.01) than those determined by cortisol (91% versus 56%). In conclusion, metanephrine provides a superior analyte compared with cortisol in assessing the selectivity of adrenal vein sampling during procedures without cosyntropin stimulation.
authors.affiliation: Department of General Internal Medicine, Medical Center, Radboud University Nijmegen, HP 463, PO Box 6500 HB Nijmegen, The Netherlands. t.dekkers@aig.umcn.nl.
authors.forename: Tanja
authors.initials: T
authors.lastname: Dekkers
authors.forename: Jaap
authors.initials: J
authors.lastname: Deinum
authors.forename: Leo J
authors.initials: LJ
authors.lastname: Schultzekool
authors.forename: Dirk
authors.initials: D
authors.lastname: Blondin
authors.forename: Oliver
authors.initials: O
authors.lastname: Vonend
authors.forename: Ad R R M
authors.initials: AR
authors.lastname: Hermus
authors.forename: Mirko
authors.initials: M
authors.lastname: Peitzsch
authors.forename: Lars C
authors.initials: LC
authors.lastname: Rump
authors.forename: Gerald
authors.initials: G
authors.lastname: Antoch
authors.forename: Fred C G J
authors.initials: FC
authors.lastname: Sweep
authors.forename: Stefan R
authors.initials: SR
authors.lastname: Bornstein
authors.forename: Jacques W M
authors.initials: JW
authors.lastname: Lenders
authors.forename: Holger S
authors.initials: HS
authors.lastname: Willenberg
authors.forename: Graeme
authors.initials: G
authors.lastname: Eisenhofer
mesh_terms: D000311:Adrenal Glands / Q000098:blood supply*; D000328:Adult; D000368:Aged; D000450:Aldosterone / Q000097:blood; D001800:Blood Specimen Collection / Q000379:methods*; D003366:Cosyntropin; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D006929:Hyperaldosteronism / Q000097:blood / Q000175:diagnosis*; D008297:Male; D008676:Metanephrine / Q000097:blood*; D008875:Middle Aged; D014680:Veins
chemical_list: D003366:Cosyntropin; D000450:Aldosterone; D008676:Metanephrine; D006854:Hydrocortisone
keywords: cortisol; cosyntropin; hyperaldosteronism; metanephrine